Prospective, randomized studies involving chemotherapy of acute leukemia, multiple myeloma, malignant lymphoma and solid tumors are being included in the cooperative activities of Acute Leukemia Groups B. BIBLIOGRAPHIC REFERENCES: Kyle, R.A.: Multiple myeloma: Review of 869 cases. Mayo Clin. Proc., 50:29-40, January, 1975. Kyle R.A. Pierre, R.V. and Bayrd, E.D.: Multiple myeloma and acute leukemia associated with alkylating agents. Arch. Intern. Med., 135:185-192, January, 1975.